In this paper, we firstly analyze system structures and working principles and functions of user management and controlling system. Secondly, we research some key technologies of network controlling deeply, such as packet filtering technology and content filtering technology. Finally, we design and implement the management and controlling software system of network controller and test it.
The most popular mail content filtering technology at present works on the application layer of network,which judges the legitimacy of the mail by analyzing the content of the mail. It can't avoid wasting the network bandwidth because of the overflowing spam.